From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 172BF33E1; Wed, 25 Jun 2025 04:42:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750826578; cv=none; b=JnrgnSRZbRGK4+vSrycJrhEvkf6Y5O4SJJLf/3YlPx1aTY9Aq4RBS3C0/y5LoLjsODRlHj9f9uwTKExiOE3dD2TDyvcj/ZAi5uibvnJSElCP/ziFmAkNI2wVu2w57/cUzkxO6HyjPtq2uJCHtd3wbH1o1rmQ34JIBPOc5tki0MM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750826578; c=relaxed/simple; bh=s0Uf4rDKwjy1dsp7E1aDOpTFmlXsypuC2uqpLNZ5DKY=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=AkGlpHHE1J4GcTEJvM5fLQfrKXJfl5kx0sYfUMoNoBhhufsJKJGcitOeHg/Emf3XlaDwvNTOPJOox4JBOmk+jvTLMEb8gnJfKy9UmBTTCJpaK53LFXTigqsqtV5rA4eSvvnsNK9Xha4E7Kbjh5OUTPtZ8JDfHBQtcNqQtoMTHvQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=kpr1HQMc; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="kpr1HQMc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 28CA3C4CEEA; Wed, 25 Jun 2025 04:42:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1750826577; bh=s0Uf4rDKwjy1dsp7E1aDOpTFmlXsypuC2uqpLNZ5DKY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=kpr1HQMca3yxYzZRwgASl7KM9m5QByPLHuYDp8quWxFse6APaNTIh2d/R6GX4wQYF zlMCV4rLSly8vPfih+25aD7oiEhIKwj+FtCtQHmXTIFp/SDYmrq3xdM37PQISvprY4 W07TOosv3dtwmSUeVemySj27HYVuIaTmksNRRLbD+Y44sPaK7s+/fycu6HqutouwWu +07mC9cMZ/h8A0LObzrYf4Z4Ajq874qs71LWj6KJVM0EM+aoy95qk7G5Q5tQoUD3We D2uO5L/oFgb6+hQYARDgkC7Xy8ugK+EpTVHaDrCI3hgXWr0GBaCRKCdXShDgD37cWK R32u0jXlYYLNQ== Date: Wed, 25 Jun 2025 13:42:54 +0900 From: Masami Hiramatsu (Google) To: Sergey Senozhatsky Cc: Ulf Hansson , Chaotian Jing , Matthias Brugger , AngeloGioacchino Del Regno , Tomasz Figa , linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org Subject: Re: [PATCH] mtk-sd: Prevent memory corruption from DMA map failure Message-Id: <20250625134254.7cbd72feb80d8d050f2f005d@kernel.org> In-Reply-To: References: <174972756982.3337526.6755001617701603082.stgit@mhiramat.tok.corp.google.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Wed, 25 Jun 2025 13:13:18 +0900 Sergey Senozhatsky wrote: > On (25/06/25 12:56), Sergey Senozhatsky wrote: > > On (25/06/12 20:26), Masami Hiramatsu (Google) wrote: > > [..] > > > @@ -1466,8 +1471,18 @@ static void msdc_ops_request(struct mmc_host *mmc, struct mmc_request *mrq) > > > WARN_ON(!host->hsq_en && host->mrq); > > > host->mrq = mrq; > > > > > > - if (mrq->data) > > > + if (mrq->data) { > > > msdc_prepare_data(host, mrq->data); > > > + if (!msdc_data_prepared(mrq->data)) { > > > + /* > > > + * Failed to prepare DMA area, fail fast before > > > + * starting any commands. > > > + */ > > > + mrq->cmd->error = -ENOSPC; > > > + mmc_request_done(mmc_from_priv(host), mrq); > > > > Do we end up having a stale/dangling host->mrq pointer here? > > Something like this maybe? Good catch! I thought it is cleared in mmc_request_done(), but not. I agree we need to clean it up since it is set in msdc_ops_request(). Reviewed-by: Masami Hiramatsu (Google) Thanks, > > --- > > diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c > index b12cfb9a5e5f..46bb770ace41 100644 > --- a/drivers/mmc/host/mtk-sd.c > +++ b/drivers/mmc/host/mtk-sd.c > @@ -1498,6 +1498,7 @@ static void msdc_ops_request(struct mmc_host *mmc, struct mmc_request *mrq) > */ > mrq->cmd->error = -ENOSPC; > mmc_request_done(mmc_from_priv(host), mrq); > + host->mrq = NULL; > return; > } > } -- Masami Hiramatsu (Google)